Pointers in go aren't a signal for optionality, they're a signal for stack or heap or optionality. They also don't play nice with interfaces.
Let's say I have a hashmap that returns a `&T` and I have a `func foo(s Stringer)`. Because 'Stringer' is an interface, it's possible for it to take both `T` and `&T` without a compile-time complaint.
In addition, I may wish to have my function `bar(t &T)` always take a pointer because I want the object to exist on the heap, or to be able to mutate its value for the caller.
Since pointers mean so many other things, they're not a good way to have a compile-error indicate optionality.
On the other hand, if my caller does `hm.Get` and gets an `Option<s: Stringer>`, it's clear what to do to pass it to foo, and if it's an `Option<&T>`, it's clear both that I want a pointer, and that it should be checked / unwrapped.
I agree that `T` / `&T` would be just as powerful as option types in go (without sum types) if pointers didn't already have other substantial meaning, and if they could sensibly interact with interfaces.
As it stands, I think you're off the mark though.
(note: All the asterisks are & because I dunno how to escape stuff on hn)
Let's say I have a hashmap that returns a `&T` and I have a `func foo(s Stringer)`. Because 'Stringer' is an interface, it's possible for it to take both `T` and `&T` without a compile-time complaint.
In addition, I may wish to have my function `bar(t &T)` always take a pointer because I want the object to exist on the heap, or to be able to mutate its value for the caller.
Since pointers mean so many other things, they're not a good way to have a compile-error indicate optionality.
On the other hand, if my caller does `hm.Get` and gets an `Option<s: Stringer>`, it's clear what to do to pass it to foo, and if it's an `Option<&T>`, it's clear both that I want a pointer, and that it should be checked / unwrapped.
I agree that `T` / `&T` would be just as powerful as option types in go (without sum types) if pointers didn't already have other substantial meaning, and if they could sensibly interact with interfaces.
As it stands, I think you're off the mark though.
(note: All the asterisks are & because I dunno how to escape stuff on hn)